Fix gh-127529: Correct asyncio.selector_events.BaseSelectorEventLoop._accept_connection's behaviour for handling ConnectionAbortedError

Author: jb2170

Lib/asyncio/selector_events.py

@@ -180,9 +180,13 @@ def _accept_connection(
                     logger.debug("%r got a new connection from %r: %r",
                                  server, addr, conn)
                 conn.setblocking(False)
-            except (BlockingIOError, InterruptedError, ConnectionAbortedError):
-                # Early exit because the socket accept buffer is empty.
-                return None
+            except ConnectionAbortedError:
+                # Discard connections that were aborted before accept().
+                continue
+            except (BlockingIOError, InterruptedError):
+                # Early exit because of a signal or
+                # the socket accept buffer is empty.
+                return
             except OSError as exc:
                 # There's nowhere to send the error, so just log it.
                 if exc.errno in (errno.EMFILE, errno.ENFILE,